Packaging machines, in general, are well known in the art and are used in a number of industrial applications. Over time, packaging machines have evolved for use in specific industry applications, for example, for use in packaging foodstuffs, and/or for use in packaging beverage containers to include groups of bottles and cans moved along a path of travel in modern high speed processing/packaging operations.
Common to most packaging machines is the use of a flighted conveyor having a spaced series of lugs or timing pins which extend upward with respect to the surface of the conveyor belt, spaced along the length of the conveyor belt. These lugs or timing pins are used to push the articles of product downstream along the path of travel, and to index the articles of product into groups as each flight is phased or pitched with respect to the other. The pitch of a flighted conveyor is generally defined as the distance between the front of one lug or timing pin to the front of the next following lug or timing pin and represents the amount of space, less the dead space, i.e. the space taken along the conveyor belt, or chain, by the lug assembly itself, and in which an article of product, or group of articles of product, can be moved along the conveyor belt in series. The use of lugs or timing pins also helps to prevent articles of product from sliding backward or out of timed relationship with one another as they are moved along the path of travel, and are particularly useful for positioning articles of product when carton blanks or paperboard carders are placed over groups of beverage containers, for example, to include bottles or cans.
As used in modern beverage packaging operations, the packaging machine is supplied with an untimed mass flow of beverage containers on a chain or belt conveyor moving the containers toward the infeed end of the packaging machine. Before being passed into the packaging machine, the untimed mass of beverage containers is typically passed through at least one star wheel to time or space the containers with respect to one another, the containers then being passed to a selector screw, which is a helical screw used to phase individual beverage containers into spaced groups of containers for delivery to the infeed end of the packaging machine. Thereafter, and in the typical packaging machines known in the art, the group of beverage containers may be enclosed within a carton blank forming a paperboard carrier for use in shipping and transporting the beverage containers.
Common to these known packaging machines is the use of flighted conveyors. A common usage of a flighted conveyor in a packaging machine is to provide an elongated chain conveyor having a spaced series of lugs or timing pins extending upwardly therefrom through a static dead plate, or a live conveyor, i.e., a moving conveyor, upon which the articles of product are slid or otherwise moved or carried along the path of travel. Flighted conveyors have proven themselves to be reliable and durable, however the use of conventional flighted conveyors is limited because the lugs or timing pins are generally fixed in position along the length of the chain conveyor, and thus the pitch, i.e., the spacing, of the groups of articles of product along the path of travel cannot be changed on the fly. Rather, in order to change the pitch of the flights, the packaging machine must be shut down and the chain conveyor either replaced with a chain conveyor having lugs set to the newly desired pitch, or the existing chain removed, the timing lugs moved and repositioned, and the chain then repositioned back on the packaging machine. All of this leads to increased production costs in handling and changing over the conveyor belts, plus delays in production time.
Essentially, once a chain conveyor with fixed lugs or timing pins is placed on the machine, the pitch of the articles of product is set and cannot be changed without changing the position of the timing pins on the belt, or changing the belt itself, all of which requires a production shutdown rather than a quick changeover on the fly. Accordingly, conventional flighted chain conveyors are not well suited for high volume high speed packaging operations where quick product size changeovers may occur. One way of solving this problem is to have several production lines with chain conveyors of differing pitches or phases for handling articles of product in differently phased or spaced groups. This, however, has the effect of increasing production costs by utilizing the duplication of packaging lines rather than requiting one single packaging line constructed to handle all needed packaging operations.
Thus, what is needed, but seemingly not available in the art, is a single packaging machine adapted for use with groups of beverage containers of differing sizes which may require different spacing or phasing along the path of travel through the packaging machine, with the ability to change the pitch of the conveyor belt along the path of travel on the fly without otherwise having to stop the packaging machine. Modem packaging operations demand flexibility and versatility which is not otherwise available in the known flighted chain conveyors in the art.
One attempt made in the prior art to overcome the problem of having fixed timing pins along the length of a chain conveyor is to raise or lower an entire series of lugs, or every other lug, along the length of a conveyor belt by raising and lowering a guide track in which the lugs are captured or guided, which has the effect of raising or lowering all of the lugs, or every other lug, in unison along the length of the conveyor. This, however, does not solve the problem of how to vary the pitch of the lugs, or flights, along the length of the conveyor belt as articles of product are still moved in a fixed series, or fixed pitch, along the length of the conveyor belt when the timing pins are raised or lowered as a group. Thus, the need still exists in the art for a variable pitch lugged conveyor belt to be used in a packaging machine adapted for handling groups of articles of product of differing sizes.
Attempts have also been made in the art to provide a flighted chain conveyor with a moving transport surface for moving a spaced series of products along a path of travel on the chain conveyor. However, the problem persists in that the lugs or these conveyors cannot be selectively moved for varying the pitch of the flights along the path of travel. Moreover, should any portion of the transport surface of the chain conveyor be damaged, removal of the chain conveyor is sometimes required in order to replace any damaged components thereof prior to resuming packaging operations. Thus, what is seemingly needed in the art, but unavailable, is a chain conveyor having an easily installed and repairable transport surface with a spaced series of variable pitch lugs provided along the length of the belt which will not otherwise require packaging machine shutdown and/or changeover of machine components in order to process series of articles of product of differing sizes phased differently with respect to one another.
Accordingly, what is needed, but not available in the art, is a packaging machine having a variable pitch lugged conveyor belt assembly which is adaptable for use with differing product shapes, sizes, and phasing or spacing requirements along the path of travel in the packaging machine; as well as a table top chain conveyor adapted for use as a part of the variable pitch lugged conveyor which maximizes machine performance and minimizes machine downtime if repair and/or replacement of chain conveyor components is required.